There has been provided a laser printer as an example of an image forming device that includes a process unit detachably mounted in a main casing and a toner cartridge mounted on the process unit. The process unit supports a photosensitive drum and a developing unit, and the toner cartridge accommodates toner.
For example, the toner cartridge includes an inner cylindrical member for accommodating toner and an outer cylindrical member for rotatably accommodating the inner cylindrical member. Both of the inner and outer cylindrical members are formed with through holes in their peripheral walls, and a handle is formed on an end face of the inner cylindrical member. The user can manipulate the handle to move (rotate) the inner cylindrical member between an opening position where the hole formed in the inner cylindrical member is opposite to the hole formed in the outer cylindrical member and a closing position where the hole formed in the inner cylindrical member is not opposite to the hole formed in the outer cylindrical member.
When the toner cartridge is detached from the process unit, the inner cylindrical member is at the closing position, and an inner peripheral surface of the outer cylindrical member opposes the hole formed in the inner cylindrical member. Thus, a fluid communication between interior and exterior of the inner cylindrical member is blocked, and toner is prevented from leaking out of the inner cylindrical member.
When the toner cartridge is mounted onto the process unit, the user manipulates the handle to rotate the inner cylindrical member to the opening position. As a result, the interior of the inner cylindrical member is brought into fluid communication with the exterior thereof, and toner accommodated in the inner cylindrical member is supplied to the developing unit.
When the toner cartridge runs out of toner, the toner cartridge is detached from the process unit for replacement after the user manipulates the handle to rotate the inner cylindrical member to the closing position.